The disposal of leaves, grass clippings and other waste plant material greatly complicates lawn maintenance. If left on a lawn, such materials will decay, forming an unsightly mat which can choke and destroy the lawn. Typically, gardeners remove these materials from lawns either by raking, or by the use of lawn mower attachments which collect such debris. In any instance, the collected leaves, grass clippings and other debris must be disposed. Disposal in a land fill or by burning is generally expensive and derogatory to the environment. Additionally, collection and disposal of plant waste represents a loss of available nutrients. In some instances, gardeners choose to compost plant waste thereby eliminating disposal problems and providing a valuable fertilizer material. Compost piles generally occupy a fairly large amount of space and tend to be malodorous; and hence, they are of limited use, particularly in urban environments.
If plant waste is chopped very finely, it may be directly applied to a lawn without danger of forming a dense mat and harming the lawn. Such finely chopped plant waste is generally referred to as "mulch" and the term "mulching" as used herein, will refer to the pulverizing or macerating of plant material to produce mulch.
It has heretofore been known to equip lawn mowers with variously configured mulching blades which finely chop grass, clippings, leaves and other plant waste. The discharge from such mulcher-equipped mowers may be safely left on a lawn to provide fertilization. U.S. Pat. Nos. 4,083,166; 4,189,903 and 3,797,212 all disclose various auxiliary mulching devices for use with rotary lawn mowers. U.S. Pat. No. 4,189,904 discloses a different design of mulcher wherein a blade bearing member at least partially blocks the outlet chute of a lawn mower restricting discharge of large size clippings. U.S. Pat. No. 4,205,510 describes a nonmulching lawn mower blade comprised of a squirrel cage fan and a number of radial cutters.
Prior art mulching attachments have not enjoyed widespread use owing to a number of problems. Particular of the mulching attachments are large, complex items which can cause severe problems of vibration and generate excessive noise in the course of their use. Additionally, such mulcher attachments are fairly heavy, hard to install, difficult to resharpen and detract from the power of the lawn mower. Mulcher attachments of the type which block discharge chutes are very prone to clog with plant matter and this problem is greatly intensified if the plant matter is even slightly wet.
What is needed is a mulching attachment which may be utilized in combination with a rotary lawn mower and which is simple to install and use, readily resharpened and/or replaced and which is lightweight and small in size so as to eliminate problems of installation, vibration and power loss.
The present invention provides a mulcher attachment for lawn mowers which may be utilized to pulverize grass clippings, leaves and other such plant waste while the lawn is being mowed. The mulcher of the present invention is of a simple design, lightweight and readily installed on existing lawn mowers or it may be incorporated in newly constructed lawn mowers. The mulcher attachment is safe, easy to use and low in cost. These and other advantages of the present invention will be readily apparent from the drawings, discussion and description which follow.